Bastrop Reservoir - 2006 Survey Report

Prepared by Marcos J. De Jesus and Stephan J. Magnelia
Inland Fisheries Division
District 2-C, San Marcos, Texas

This is the authors' summary from a 32-page report. For a copy of the complete report, use the download link in the sidebar.

Fish populations in Bastrop Reservoir were surveyed in 2006 using electrofishing and in 2007 using gill nets. An angler creel survey was also conducted in 2004. This report summarizes the results of the surveys and contains a fisheries management plan for the reservoir based on those findings.

Reservoir Description

Bastrop Reservoir is a 906-acre impoundment of Spicer Creek, a tributary of the Colorado River, and is located approximately 3 miles northeast of the City of Bastrop, Bastrop County, Texas. The dam was constructed in 1965 to supply water for cooling a natural-gas-fired power plant operated by the Lower Colorado River Authority (LCRA). The reservoir has a shoreline development index of 10.5, and lies within a unique ecological area known as the Lost Pines, a 70 square mile area of the Post Oak Savannah ecological area comprised of loblolly pine forests.

Management History

Important sport fish include largemouth bass and catfishes. The Florida subspecies of largemouth bass was last stocked in Bastrop Reservoir in 1992 to increase Florida bass genetic influence. A 14- to 21-inch slot limit for largemouth bass with a 5 fish daily bag limit (one greater than 21 inches) was implemented in 1993.

Fish Community

• Prey species: Bluegill, threadfin shad, and redear sunfish were the dominant prey species available.
• Catfishes: Channel catfish was the dominant species present. It was the second most sought after species by anglers at the reservoir. Flathead catfish were also present in lower density.
• Largemouth bass: Largemouth bass were abundant. It was the most sought after species by anglers at the reservoir. Anglers released most of all largemouth bass caught. Growth rates to 14 inches remained good, while large fish (>21 inches) were rare.

Management Strategies

Based on current information, alternate management schemes should be considered. The 14-21-inch slot length limit on largemouth bass has not helped increase the angler and electrofishing catch of bass > 21 inches due to the poor growth once individuals enter the protected slot. Largemouth bass reach 14 inches between their second and third year of growth. However, after the third year, growth rates decrease considerably. Based on electrofishing results, only 3 to 4% of the population exceeds 18 inches (13.2% of the slot fish, based on 2006 electrofishing survey). Intraspecific competition may be contributing to slow growth of older fish. An alternate forage source should be investigated to help increase growth of these larger individuals, along with the promotion of harvest of sub-slot bass. Channel catfish are abundant, yet underutilized. Fishing opportunities for this species should be promoted to the public. Aquatic vegetation coverage, including hydrilla, typically varies among years. Aquatic plant coverage should be monitored annually. Aquatic plant coverage may help explain fisheries trends.

Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-32 Statewide Freshwater Fisheries Monitoring and Management Program